Sixth and eighth residues replaced with amino acid Tbt.
A series of peptides (LFB0053 to LFB0064) where the two Trp residues in positions 6 and 8 were replaced by large aromatic amino acids were prepared and tested for antibacterial activity against Escherichia coli and Staphylococcus aureus to investigat how the biological activity of LFB peptides (LFB0031) can be affected by employing different aromatic amino acids. In conclusion, introducing unnatural aromatic amino acids that have larger volumes than Trp can increase the antibacterial activity of lactoferricin derivatives (Citation: 1).